An alkali agent blended into a first part in an oxidizing hair dye or bleaching agent is used for improving a bleaching effect and a hair dyeing effect, and activating an activity of an oxidizing agent blended into a second part to promote the oxidative degradation of melanin granules in hair so that a bright color tone may be obtained. Although ammonia has been generally used as the alkali agent, ammonia has a strong pungent odor. Attempts have been made to use, for example, alkanolamines instead of ammonia in order to reduce the pungent odor of ammonia (see, for example, Patent Document 1). However, the alkanolamines involve some problems, in that, the alkanolamines also have their unique unpleasant odors, and do not have enough bleaching performance for providing hair with a bright tinge. Therefore, an oxidizing hair dye or bleaching agent which enables not only to prevent generation of pungent odor or unpleasant odor but also to provide bleaching performance sufficient for providing hair with a bright tinge has been desired.    [Patent Document 1] JP-A-01-213220